Abundance, composition, sustainable yield, and risk analysis of the northern pike population in Harding Lake, 1998
By: by Stafford M. Roach and Julie McIntyre.
Contributors: McIntyre, Julie.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 99-31.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1999
Place of publication: Anchorage
Language: eng
Number of pages: 43
Subjects: Pike -- Alaska -- Harding Lake -- Statistics.; Fish populations -- Alaska -- Harding Lake -- Statistics.
Other titles: Federal aid in sport fish restoration (Alaska)
Description: In 1998, estimated abundance of northern pike esox lucius within Harding Lake was 1,376 fish (SE = 279) 300 mm FL, 934 fish (SE = 191) 450 mm FL, and 190 fish (SE = 43) 625 mm FL. Estimated density of northern pike 300 mm FL was 1.38 (SE = 0.28) fish per hectare. The estimated proportion of the population that was between 300 and 449 mm FL was 0.32 (SE = 0.02); between 450 and 624 mm FL was 0.54 (SE = 0.02); and, 625 mm FL was 0.14 (SE = 0.01). In 1998, estimated recruitment (abundance of age-5 fish) was 284 northern pike (SE = 58). Estimated abundance was 361 fish (SE = 73) < age-5 and 731 fish (SE = 180) > age-5. The mean error in assigning the proper incremental age from the scales of 48 northern pike recaptured in 1998 from 1997 was -0.35 years (Z = 2.15; P 0.01); 0.40 years (Z = 1.46; P=0.14) for 10 northern pike that were age-4 in 1997; and -0.55 years (Z = 2.97; P0.01) for 38 northern pike age-5 in 1997. The estimated average percent error of the scale reader in reproducing the same age twice from a Harding Lake northern pike scale in 1998 was 2.4%. For Harding Lake northern pike, the indirect value for maximum sustainable yield was estimated as 414 fish, the number of northern pike needed to produce maximum sustainable yield was estimated as 1,728 spawning size fish, and the carrying capacity of Harding Lake was estimated as 3,457 northern pike age-5. In contrast, using Rickers stock recruitment model, maximum sustainable yield was estimated as 368 fish and the number of spawners needed to produce maximum sustainable yield was estimated as 576 spawning size fish. Risk analysis indicated that, under current regulations and fishing pressure, there is a high risk that this northern pike population will ( 300 mm FL) remain under 1,500 fish. A change in minimum length from 26 in (~625 mm FL) to 30 in (~725 mm FL) would reduce this risk considerably.
Notes: "November 1999."

Includes bibliographical references (p. 22-24).

Also issued online.

Partially financed by the Federal Aid in Sport Fish Restoration Act. Project F-10-14, Job No. R-3-4(c)